LED package set and LED bulb including same

ABSTRACT

An LED package set including a substrate, a first LED package disposed on the substrate and including at least one first LED chip, a second LED package disposed on the substrate and including at least one second LED chip, and a resistor disposed on the substrate, connected to the first LED package in series, and connected to the second LED package in parallel, in which the second LED package is connected in parallel to the first LED package and the resistor, and the first LED package and the second LED package are configured to emit light having different color temperatures.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a National Stage Entry of International ApplicationNo. PCT/KR2018/006137, filed on May 30, 2018, and claims priority fromand the benefit of Korean Patent Application No. 10-2017-0067992, filedon May 31, 2017, each of which is hereby incorporated by reference forall purposes as if fully set forth herein.

BACKGROUND Field

Exemplary embodiments of the invention relate generally to an LEDpackage set and an LED bulb including the same.

Discussion of the Background

Conventionally, incandescent lamps using filaments have been widely usedas luminaires. A filament-based incandescent lamp generally emits lightby temperature radiation, which may occur when a tungsten filament isheated in a vacuum glass bulb to high temperature through application ofelectricity.

Such a typical incandescent lamp is not suitable for long-term use dueto short lifespan of the filament and extremely low energy efficiency,since most of energy supplied thereto is released as heat and only afraction of the energy is converted into light.

Recently, light emitting diodes (LEDs) having long lifespan and highenergy efficiency are used in luminaires.

The above information disclosed in this Background section is only forunderstanding of the background of the inventive concepts, and,therefore, it may contain information that does not constitute priorart.

SUMMARY

LED packages and LED bulbs including the same constructed according toexemplary embodiments of the invention are capable of providing higheconomic efficiency due to long lifespan and low heat generation.

Exemplary embodiments also provide an LED package set, which allowsregulation of color temperature of light emitted therefrom, and an LEDbulb including the same.

Exemplary embodiments further provide an LED package set, which canevenly emit light in all directions by emitting light in differentdirections, and an LED bulb including the same.

Additional features of the inventive concepts will be set forth in thedescription which follows, and in part will be apparent from thedescription, or may be learned by practice of the inventive concepts.

An LED package set according to an exemplary embodiment includes asubstrate, a first LED package disposed on the substrate and includingat least one first LED chip, a second LED package disposed on thesubstrate and including at least one second LED chip, and a resistordisposed on the substrate, connected to the first LED package in series,and connected to the second LED package in parallel, in which the secondLED package is connected in parallel to the first LED package and theresistor, and the first LED package and the second LED package areconfigured to emit light having different color temperatures.

The substrate may include a pair of electrode pads, each of the firstLED package, second LED package, and the resistor may include a firstend and a second end opposing the first end, the first end of the firstLED package and the first end of the second LED package may be connectedto one of the pair of electrode pads, the first end of the resistor maybe connected to the second end of the first LED package, and the secondend of the second LED package and the second end of the resistor may beconnected to the other one of the pair of electrode pads.

Light from the first LED package may have a higher color temperaturethan light from the second LED package.

A difference in color temperature between light from the first LEDpackage and light from the second LED package may be at least 500 K.

A difference in color temperature between light from the first LEDpackage and light from the second LED package may be less than or equalto 1,000 K.

Current may be distributed to the first LED package and the second LEDpackage depending a resistance formed by the first LED package and theresistor connected in series, and a resistance of the second LEDpackage.

A color temperature of a mixture of light from the first LED package andthe second LED package may change depending on current flowing throughthe first LED package and current flowing through the second LEDpackage.

The first LED package may include a first wavelength conversion portioncovering the at least one first LED chip, and the second LED package mayinclude a second wavelength conversion portion covering the at least onesecond LED chip.

The first LED chip and the second LED chip may be configured to emitlight having the same color temperature.

The first wavelength conversion portion and the second wavelengthconversion portion may include phosphors having different colortemperatures, respectively.

The LED package set may further include a wavelength conversion portioncovering each the first LED chip and the second LED chip.

The first LED chip and the second LED chip may be configured to emitlight having different color temperatures.

An LED bulb according to another exemplary embodiment includes a baseincluding an external electrode pad to receive electricity from anexternal power supply, an LED package set including a substrate thatincludes a pair of electrode pads disposed at one end thereof, a firstLED package including at least one first LED chip, a second LED packageincluding at least one second LED chip, and a resistor, a holderincluding a connection portion to receive one end of the LED packageset, and electrically connected to the pair of electrode pads of thesubstrate, and a light transmissive cover enclosing the LED package setand coupled to the base, in which the first LED package, the second LEDpackage, and the resistor are disposed on the substrate, the first LEDpackage and the second LED package are connected in parallel, and areconfigured to emit light having different color temperatures, and theresistor is connected to the first LED package in series and connectedto the second LED package in parallel.

Each of the first LED package, second LED package, and the resistor mayinclude a first end and a second end opposing the first end, the firstend of the first LED package and the first end of the second LED packagemay be connected to one of the pair of electrode pads, the second end ofthe resistor may be connected to the second end of the first LEDpackage, and the second end of the second LED package and the second endof the resistor may be connected to the other one of the pair ofelectrode pads.

Light from the first LED package may have a higher color temperaturethan light from the second LED package.

A difference in color temperature between light from the first LEDpackage and light from the second LED package may be in a range of 500 Kto 1,000 K.

The connection portion of the holder may include a groove or hole, towhich one end of the substrate is inserted, and the connection portionmay include a pair of connection terminals electrically connected to thepair of electrode pads of the substrate.

The substrate may further include a bent portion disposed between thepair of electrode pads and the first LED chip, the second LED chip, andthe resistor, by which the substrate is bent in an upwards or downwardsdirection.

The first LED package may include a first wavelength conversion portioncovering the first LED chip, the second LED package may include a secondwavelength conversion portion covering the second LED chip, the firstLED chip and the second LED chip may be configured to emit light havingthe same color temperature, and the first wavelength conversion portionand the second wavelength conversion portion may include phosphorshaving different color temperatures, respectively.

The LED bulb may further include a wavelength conversion portioncovering each of the first LED chip and the second LED chip, in whichthe first wavelength conversion portion and the second wavelengthconversion portion may include phosphors having different colortemperatures, respectively.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory and areintended to provide further explanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention and are incorporated in and constitute apart of this specification, illustrate exemplary embodiments of theinvention, and together with the description serve to explain theinventive concepts.

FIG. 1 and FIG. 2 are views of an LED package set according an exemplaryembodiment.

FIG. 3 is a circuit diagram of the LED package set according to anexemplary embodiment.

FIG. 4 and FIG. 5 are views of an LED bulb according to anotherexemplary embodiment.

FIG. 6 is a view of an LED bulb according to still another exemplaryembodiment.

DETAILED DESCRIPTION

In the following description, for the purposes of explanation, numerousspecific details are set forth in order to provide a thoroughunderstanding of various exemplary embodiments or implementations of theinvention. As used herein “embodiments” and “implementations” areinterchangeable words that are non-limiting examples of devices ormethods employing one or more of the inventive concepts disclosedherein. It is apparent, however, that various exemplary embodiments maybe practiced without these specific details or with one or moreequivalent arrangements. In other instances, well-known structures anddevices are shown in block diagram form in order to avoid unnecessarilyobscuring various exemplary embodiments. Further, various exemplaryembodiments may be different, but do not have to be exclusive. Forexample, specific shapes, configurations, and characteristics of anexemplary embodiment may be used or implemented in another exemplaryembodiment without departing from the inventive concepts.

Unless otherwise specified, the illustrated exemplary embodiments are tobe understood as providing exemplary features of varying detail of someways in which the inventive concepts may be implemented in practice.Therefore, unless otherwise specified, the features, components,modules, layers, films, panels, regions, and/or aspects, etc.(hereinafter individually or collectively referred to as “elements”), ofthe various embodiments may be otherwise combined, separated,interchanged, and/or rearranged without departing from the inventiveconcepts.

The use of cross-hatching and/or shading in the accompanying drawings isgenerally provided to clarify boundaries between adjacent elements. Assuch, neither the presence nor the absence of cross-hatching or shadingconveys or indicates any preference or requirement for particularmaterials, material properties, dimensions, proportions, commonalitiesbetween illustrated elements, and/or any other characteristic,attribute, property, etc., of the elements, unless specified. Further,in the accompanying drawings, the size and relative sizes of elementsmay be exaggerated for clarity and/or descriptive purposes. When anexemplary embodiment may be implemented differently, a specific processorder may be performed differently from the described order. Forexample, two consecutively described processes may be performedsubstantially at the same time or performed in an order opposite to thedescribed order. Also, like reference numerals denote like elements.

When an element, such as a layer, is referred to as being “on,”“connected to,” or “coupled to” another element or layer, it may bedirectly on, connected to, or coupled to the other element or layer orintervening elements or layers may be present. When, however, an elementor layer is referred to as being “directly on,” “directly connected to,”or “directly coupled to” another element or layer, there are nointervening elements or layers present. To this end, the term“connected” may refer to physical, electrical, and/or fluid connection,with or without intervening elements. Further, the D1-axis, the D2-axis,and the D3-axis are not limited to three axes of a rectangularcoordinate system, such as the x, y, and z-axes, and may be interpretedin a broader sense. For example, the D1-axis, the D2-axis, and theD3-axis may be perpendicular to one another, or may represent differentdirections that are not perpendicular to one another. For the purposesof this disclosure, “at least one of X, Y, and Z” and “at least oneselected from the group consisting of X, Y, and Z” may be construed as Xonly, Y only, Z only, or any combination of two or more of X, Y, and Z,such as, for instance, XYZ, XYY, YZ, and ZZ. As used herein, the term“and/or” includes any and all combinations of one or more of theassociated listed items.

Although the terms “first,” “second,” etc. may be used herein todescribe various types of elements, these elements should not be limitedby these terms. These terms are used to distinguish one element fromanother element. Thus, a first element discussed below could be termed asecond element without departing from the teachings of the disclosure.

Spatially relative terms, such as “beneath,” “below,” “under,” “lower,”“above,” “upper,” “over,” “higher,” “side” (e.g., as in “sidewall”), andthe like, may be used herein for descriptive purposes, and, thereby, todescribe one elements relationship to another element(s) as illustratedin the drawings. Spatially relative terms are intended to encompassdifferent orientations of an apparatus in use, operation, and/ormanufacture in addition to the orientation depicted in the drawings. Forexample, if the apparatus in the drawings is turned over, elementsdescribed as “below” or “beneath” other elements or features would thenbe oriented “above” the other elements or features. Thus, the exemplaryterm “below” can encompass both an orientation of above and below.Furthermore, the apparatus may be otherwise oriented (e.g., rotated 90degrees or at other orientations), and, as such, the spatially relativedescriptors used herein interpreted accordingly.

The terminology used herein is for the purpose of describing particularembodiments and is not intended to be limiting. As used herein, thesingular forms, “a,” “an,” and “the” are intended to include the pluralforms as well, unless the context clearly indicates otherwise. Moreover,the terms “comprises,” “comprising,” “includes,” and/or “including,”when used in this specification, specify the presence of statedfeatures, integers, steps, operations, elements, components, and/orgroups thereof, but do not preclude the presence or addition of one ormore other features, integers, steps, operations, elements, components,and/or groups thereof. It is also noted that, as used herein, the terms“substantially,” “about,” and other similar terms, are used as terms ofapproximation and not as terms of degree, and, as such, are utilized toaccount for inherent deviations in measured, calculated, and/or providedvalues that would be recognized by one of ordinary skill in the art.

As customary in the field, some exemplary embodiments are described andillustrated in the accompanying drawings in terms of functional blocks,units, and/or modules. Those skilled in the art will appreciate thatthese blocks, units, and/or modules are physically implemented byelectronic (or optical) circuits, such as logic circuits, discretecomponents, microprocessors, hard-wired circuits, memory elements,wiring connections, and the like, which may be formed usingsemiconductor-based fabrication techniques or other manufacturingtechnologies. In the case of the blocks, units, and/or modules beingimplemented by microprocessors or other similar hardware, they may beprogrammed and controlled using software (e.g., microcode) to performvarious functions discussed herein and may optionally be driven byfirmware and/or software. It is also contemplated that each block, unit,and/or module may be implemented by dedicated hardware, or as acombination of dedicated hardware to perform some functions and aprocessor (e.g., one or more programmed microprocessors and associatedcircuitry) to perform other functions. Also, each block, unit, and/ormodule of some exemplary embodiments may be physically separated intotwo or more interacting and discrete blocks, units, and/or moduleswithout departing from the scope of the inventive concepts. Further, theblocks, units, and/or modules of some exemplary embodiments may bephysically combined into more complex blocks, units, and/or moduleswithout departing from the scope of the inventive concepts.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which this disclosure is a part. Terms,such as those defined in commonly used dictionaries, should beinterpreted as having a meaning that is consistent with their meaning inthe context of the relevant art and should not be interpreted in anidealized or overly formal sense, unless expressly so defined herein.

FIG. 1 and FIG. 2 are views of an LED package set according to anexemplary embodiment.

In particular, FIG. 1 is a plan view of an LED package set 100 accordingto an exemplary embodiment, and FIG. 2 is a cross-sectional view takenalong line A1-A2 of the LED package set 100 of FIG. 1.

Referring to FIG. 1 and FIG. 2, the LED package set 100 includes asubstrate 140, a first LED package 110, a second LED package 120, and aresistor 130. The LED package set 100 may be driven in a constantcurrent mode.

The substrate 140 is a circuit substrate having a wiring circuit formedthereon. For example, the substrate 140 may be any substrate suitablefor forming a wiring circuit thereon, such as a printed circuit board, ametal substrate, and a glass substrate. In some exemplary embodiments,the substrate 140 may be a metal substrate having high heat dissipationperformance, which may allow a plurality of LED chips or LED packages tobe disposed thereon.

The substrate 140 includes a pair of electrode pads 141 formed at oneend thereof. The pair of electrode pads 141 receives electricity fordriving the first LED package 110 and the second LED package 120 fromthe outside of the LED package set 100. In this case, electricityapplied to the substrate 140 may be changed according to a dimmingsignal.

The pair of electrode pads 141 formed on the substrate 140 iselectrically connected to the first LED package 110, the second LEDpackage 120, and the resistor 130.

The first LED package 110 is disposed on the substrate 140. The firstLED package 110 includes a first LED chip 111 and a first wavelengthconversion portion 115.

The first LED package 110 may include at least one first LED chip 111.In this case, the first LED chips 111 of the first LED package 110 maybe electrically connected to one another and form an array.

The first wavelength conversion portion 115 is formed on the substrate140 and cover the first LED chip 111. The first wavelength conversionportion 115 may be formed to collectively cover multiple first LED chips111. Alternatively, the first wavelength conversion portion 115 may beformed to individually cover each of the first LED chips 111.

The second LED package 120 is disposed on the substrate 140. The secondLED package 120 includes a second LED chip 121 and a second wavelengthconversion portion 125.

The second LED package 120 may include at least one second LED chip 121.When the second LED package 120 includes multiple second LED chips 121,the second LED chips 121 may be electrically connected to one anotherand form an array.

The second wavelength conversion portion 125 is formed on the substrate140 and cover the second LED chip 121. The second wavelength conversionportion 125 may be formed to collectively cover multiple second LEDchips 121. Alternatively, the second wavelength conversion portion 125may be formed to individually cover each of the second LED chips 121.

The first LED package 110 and the second LED package 120 emit light ofthe same color. In addition, light from the first LED package 110 has adifferent color temperature than light from the second LED package 120.For example, the first LED package 110 and the second LED package 120may emit white light having different color temperatures.

Light emitted from the first LED chip 111 and the second LED chip 121 iswarm light. For example, light emitted from the first LED chip 111 andthe second LED chip 121 has a color temperature of 1,000 K to 4,000 K.In some exemplary embodiments, light emitted from the first LED chip 111and the second LED chip 121 has a color temperature of 1,600 K to 3,000K.

In addition, the first wavelength conversion portion 115 and the secondwavelength conversion portion 125 include different phosphors. Thus,light emitted from the first LED package 110 through the firstwavelength conversion portion 115 has a different color temperature thanlight emitted from the second LED package 120 through the secondwavelength conversion portion 125.

According to an exemplary embodiment, the first wavelength conversionportion 115 includes a phosphor having a higher color temperature. Forexample, the first wavelength conversion portion 115 may include aphosphor having a color temperature of about 3,000 K. In addition, thesecond wavelength conversion portion 125 includes a phosphor having alower color temperature. For example, the second wavelength conversionportion 125 may include a phosphor having a color temperature of about1,800 K.

Accordingly, light from the first LED package 110 has a higher colortemperature than light from the second LED package 120. However, theinventive concepts are not limited thereto. For example, in an LEDpackage according to another exemplary embodiment, light from the secondLED package 120 has a higher color temperature than light from the firstLED package 110, when light from the first LED package 110 and lightfrom the second LED package 120 has a different color temperature fromeach other.

A difference in color temperature between light from the first LEDpackage 110 and light from the second LED package 120 may range from 500K to 1,000 K.

An LED package having a lower color temperature may have a lower lightintensity than an LED package having a higher color temperature. Thus,in order to supplement light intensity of the second LED package 120having a lower color temperature, the second LED chip 121 may have awider light emitting area than the first LED chip 111. In particular,the second LED chip 121 may be larger than the first LED chip 111.

The resistor 130 may be disposed on the substrate 140 or embedded in thesubstrate 140. The resistor 130 may have a fixed resistance. Theresistor 130 is adapted to distribute current to the first LED package110 and the second LED package 120.

Although a wiring circuit is not shown in FIG. 1, the first LED package110 is connected in series to the resistor 130. Further, the second LEDpackage 120 is connected in parallel to the first LED package 110 andthe resistor 130, which are connected in series.

The LED package set 100 according to the illustrated exemplaryembodiment emits a mixture of light having different color temperatures.

Voltage changed in magnitude according to an external dimming signal isapplied to the LED package set 100. A resistance ratio of the first LEDpackage 110 to the second LED package 120 is changed depending on thechange in voltage and the resistor 130.

Current is distributed to the first LED package 110 and the second LEDpackage 120 in accordance to an inverse relationship to the resistanceratio.

As used herein, the dimming signal may refer to a signal that controlsthe magnitude of electricity applied to the substrate 140 to regulatecolor temperature of light emitted from the LED package set 100.

As current flowing through the first LED package 110 and the second LEDpackage 120 is changed, the strength or brightness of light emitted fromeach of the first LED package 110 and the second LED package 120 ischanged. Accordingly, a color temperature of mixed light from the LEDpackage set 100 is regulated by the change in strength or brightnessratio between light from the first LED package 110 and light from thesecond LED package 120 having different color temperatures.

In the illustrated exemplary embodiment, the first LED package 110 andthe second LED package 120 are described as including the firstwavelength conversion portion 115 and the second wavelength conversionportion 125, respectively. However, the inventive concepts are notlimited thereto. For example, in some exemplary embodiments, the firstwavelength conversion portion 115 and the second wavelength conversionportion 125 may be omitted, when each of the first LED chip 111 and thesecond LED chip 121 emits light having a color and color temperaturedesired by a user.

In addition, the LED package set 100 according to the illustratedexemplary embodiment is described as including two LED packages emittinglight having different color temperatures. However, the inventiveconcepts are not limited thereto. For example, in some exemplaryembodiments, the LED package set 100 may include three or more LEDpackages emitting light having different color temperatures. In thiscase, the color temperature of light emitted from the LED package set100 can be more accurately regulated by adjusting the resistance ofresistors connected in series to the LED packages.

According to another exemplary embodiment, the first LED chip 111 of thefirst LED package 110 and the second LED chip 121 of the second LEDpackage 120 may emit light having different color temperatures. In thiscase, the first LED package 110 and the second LED package 120 may becovered by a single common wavelength conversion portion.

According to still another exemplary embodiment, the first LED chip 111of the first LED package 110 and the second LED chip 121 of the secondLED package 120 may emit light having the same color temperature. Moreparticularly, the first LED chip 111 may be the same as the second LEDchip 121. In this case, the first wavelength conversion portion 115 ofthe first LED package 110 and the second wavelength conversion portion125 of the second LED package 120 may include phosphors having differentcolor temperatures, respectively.

FIG. 3 is a circuit diagram of an LED package set according to anexemplary embodiment.

An LED package set 100 represented by the circuit of FIG. 3 is the LEDpackage set 100 of FIG. 1 and FIG. 2.

Referring to FIG. 3, a first LED array 113 of the first LED package (110of FIG. 1) is connected in series to the resistor 130. Here, one end ofthe resistor 130 is connected to a cathode of the first LED array 113,in particular, the other end of the first LED array. In addition, asecond LED array 123 of the second LED package (120 of FIG. 2) isconnected in parallel to the first LED array 113 and the resistor 130,which are connected in series. An anode of the first LED array 113 andan anode of the second LED array 123 are connected to a first terminal151. In addition, the other end of the resistor 130 and a cathode of thesecond LED array 123 are connected to a second terminal 152. The firstterminal 151 and the second terminal 152 are connected to opposite endsof a constant current system 160, respectively. The resistor 130 has apredetermined fixed resistance. As used herein, the constant currentsystem 160 is a system that supplies electricity to the LED package set100 in a constant current mode.

Electricity applied to the LED package set 100 is changed according toan external dimming signal. More particularly, voltage and currentapplied to the LED package set 100 are changed according to the externaldimming signal. As voltage applied to the LED package set 110 is changedaccording to the dimming signal, a ratio between a resistance formed bythe first LED package 110 and the resistor 130, and a resistance by thesecond LED package 120 is changed. Current from the constant currentsystem 160 is distributed to the first LED package 110 and the secondLED package 120 in inverse relationship to the ratio.

Hereinafter, the following example will be described with an assumptionthat the dimming signal indicates a dimming level of 100% when the lightintensities of the first LED package (110 of FIG. 1) and the second LEDpackage (120 of FIG. 2) reach the same maximum values, and that currentapplied to the LED package set has a maximum value of 30 mA.

In this example, the first LED package (110 of FIG. 1) has a colortemperature of 3,000 K and the second LED package (120 of FIG. 2) has acolor temperature of 1,800 K. Further, the resistor 130 has a resistanceof 1 kΩ.

At a dimming level of 10%, a current of 3 mA is applied to the firstterminal 151. In this case, all of the current flows through the secondLED package (120 of FIG. 2). Thus, the first LED package (110 of FIG. 1)is in an OFF state. The second LED package (120, FIG. 2) emits lighthaving an intensity corresponding to 3 mA. Since only the second LEDpackage (120 of FIG. 2) emits light, light from the LED package set 100has a color temperature of 1,800 K.

At a dimming level of 20%, a current of 6 mA is applied to the firstterminal 151. In this case, a current of 1.2 mA flows through the firstLED package (110 of FIG. 1) and a current of 4.8 mA flows through thesecond LED package (120 of FIG. 2). As a result, the LED package set 100emits light having a color temperature of 2,100 K.

At a dimming level of 50%, a current of 15 mA is applied to the firstterminal 151. In this case, a current of 4.5 mA flows through the firstLED package (110 of FIG. 1) and a current of 10.5 mA flows through thesecond LED package (120 of FIG. 2). As a result, the LED package set 100emits light having a color temperature of 2,400 K.

At a dimming level of 75%, a current of 22.5 mA is applied to the firstterminal 151. In this case, a current of 9 mA flows through the firstLED package (110 of FIG. 1) and a current of 13.5 mA flows through thesecond LED package (120 of FIG. 2). As a result, the LED package set 100emits light having a color temperature of 2,550 K.

At a dimming level of 100%, a current of 30 mA is applied to the firstterminal 151. In this case, a current of 15 mA flows through each of thefirst LED package (110 of FIG. 1) and the second LED package (120 ofFIG. 2). As a result, the LED package set 100 emits light having a colortemperature of 2,700 K.

In this manner, the LED package set 100 according to the illustratedexemplary embodiment can emit light having various color temperatures bydistributing current to the first LED package (110 of FIG. 1) and thesecond LED package (120 of FIG. 2) according to the dimming signal.

FIG. 4 and FIG. 5 are exemplary views of an LED bulb according toanother exemplary embodiment.

FIG. 4 is an exemplary view of a base 170 and a holder 180 of an LEDbulb 10, and FIG. 5 is an exemplary view of the LED bulb 10 with an LEDpackage set 100 mounted on the base 170 and the holder 180 of FIG. 4.

Referring to FIGS. 4 and 5, the LED bulb 10 includes the base 170, theLED package set 100, the holder 180, and a light transmissive cover 190.The LED package set 100 may be the LED package set 100 described abovewith reference to FIG. 1 to FIG. 3.

The base 170 is coupled to a socket for connection to an external powersupply. The base 170 includes a first external electrode 171 and asecond external electrode 172 formed on an outer surface thereof andelectrically connected to the socket. The first external electrode 171and the second external electrode 172 receive electricity from theexternal power supply.

The light transmissive cover 190 is coupled to the base 170 to encloseinternal components, such as the holder 180 and the LED package set 100.The light transmissive cover 190 is formed of a light transmissivematerial. For example, the light transmissive cover 190 is formed ofglass.

The holder 180 and the LED package set 100 are disposed in the LED bulb10. An interior of the LED bulb 10 may be an inner space defined whenthe base 170 is coupled to the light transmissive cover 190.

The holder 180 is disposed under the LED package set 100 to support theLED package set 100 in an upright position. Referring to FIG. 4, theholder 180 includes a connection portion 181 provided in the form of agroove or a through-hole. The connection portion 181 includes a pair ofconnection terminals 183 formed of a conductive material. One of thepair of connection terminals 183 is electrically connected to the firstexternal electrode 171 of the base 170, and the other connectionterminal 183 is electrically connected to the second external electrode172 of the base 170. The pair of connection terminals 183 is connectedto the first external electrode 171 and the second external electrode172 of the base 170 via conductive parts, such as wires, respectively.In the illustrated exemplary embodiment, the holder 180 is beingdescribed as a separate component from the base 170. However, theinventive concepts are not limited thereto, and in some exemplaryembodiments, the holder 180 may be integrally formed with the base 170.

The LED bulb 10 includes at least one LED package set 100. In FIG. 5,the LED bulb 10 is shown as including four LED package sets 100.However, the inventive concepts are not limited thereto, and the numberof LED package sets 100 mounted on the LED bulb 10 may be varied asneeded.

The LED package set 100 is secured to the holder 180. One end of the LEDpackage set 100 is inserted into the connection portion 181 of theholder 180. Thus, the LED package set 100 is disposed in an uprightposition inside the LED bulb 10. More particularly, the LED package set100 may be disposed, such that the first LED package 110 and the secondLED package 120 face an inner surface of the light transmissive cover190.

In addition, the one end of the LED package set 100 inserted into theconnection portion 181 corresponds to one end of the substrate 140, atwhich the pair of electrode pads 141 is formed. When the one end of theLED package set 100 is inserted into the connection portion 181, thepair of connection terminals 183 of the connection portion 181 isbrought into contact with and electrically connected to the pair ofelectrode pads 141 of the substrate 140. Accordingly, electricitychanged according to the dimming signal is applied to the LED packageset 100 through the first external electrode 171 and the second externalelectrode 172 of the base 170 and the pair of connection terminals 183of the holder 180.

Since the LED bulb 10 has a configuration, in which the LED package set100 is secured by being inserted into the holder 180, the LED packageset 100 may be easily replaced upon failure of the LED package set 100.

According to the exemplary embodiments, the LED package set 100 allowslight intensities of the first LED package 110 and the second LEDpackage 120 to be regulated depending on current applied thereto. Inparticular, the color temperature of light emitted from the LED bulb 10is changed in accordance with the change in current applied from theoutside. Thus, the LED bulb 10 can emit light having a color temperaturesuitable for a specific application or environment.

In addition, according to the exemplary embodiments, the LED package set100 includes the resistor 130 connected in series to the first LEDpackage 110, and connected in parallel to the second LED package 120. Inaddition, current is distributed to the first LED package 110 and thesecond LED package 120 depending on the resistance formed by the firstLED package 110 and the resistor 130, and the resistance of the secondLED package 120. Thus, the LED bulb 10 can emit light, in which a colortemperature thereof may be changed according to the dimming signal.

In addition, according to the exemplary embodiments, the LED bulb 10 canevenly emit light laterally by including the plurality of LED packagesets 100.

FIG. 6 is an exemplary view of an LED bulb according to still anotherexemplary embodiment.

The LED bulb 20 according to the illustrated exemplary embodiment issubstantially the same as the LED bulb 20 of FIG. 5, and thus, repeateddescriptions of the substantially the same components thereof will beomitted to avoid redundancy.

Referring to FIG. 6, the LED bulb 20 according to the illustratedexemplary embodiment includes at least one LED package set 200. The LEDpackage set 200 is formed with a bent portion 210. The bent portion 210is formed on the substrate 140 between the pair of electrode pads 141and the first LED chip 111, the second LED chip 121, and the resistor130. In addition, the bent portion 210 is formed in a transversedirection of the substrate 140. As used herein, the transverse directionof the substrate 140 is a perpendicular direction with respect to astraight line connecting one end of the substrate 140, at which the pairof electrode pads 141 is formed, to the other end of the substrate 140.

The bent portion 210 is provided to bend the LED package set 200 at apredetermined angle. The bent portion 210 may be formed in any shape andby any method, so long as the LED package set 200 can be bent withrespect to the bent portion 210. For example, the bent portion 210 maybe formed by half-etching a portion of the substrate 140. Alternatively,the bent portion 210 may be provided in the form of at least onethrough-hole formed through a portion of the substrate 140. Stillalternatively, the bent portion 210 may be provided in the form of anindentation formed by pressing a pointed object into a portion of thesubstrate 140.

The LED package set 200 may be bent with respect to the bent portion210, such that the first LED package 110 and the second LED package 120face in an upward direction of the LED bulb 20, as shown in FIG. 6.

In this manner, the LED bulb 20 including the LED package sets 200 asshown in FIG. 6 can evenly emit light upwards as well as laterally.

Alternatively, the LED bulb 20 may include an LED package set 200 bentdownwards, as opposed to FIG. 6, to evenly emit light laterally anddownwards. Still alternatively, the LED bulb 20 may include both an LEDpackage set bent upwards and an LED package set bent downwards to evenlyemit light laterally, upwards, and downwards.

According to exemplary embodiments, an LED package set and an LED bulbincluding the same can have long lifespan and low heat generation byemploying an LED package, instead of a tungsten filament, therebyimproving economic efficiency.

In addition, the LED package set and the LED bulb including the same canemit light having a suitable color temperature according to anenvironment by using at least two LED packages emitting light havingdifferent color temperatures.

Further, the LED package set and the LED bulb including the same includea resistor connected in series to one LED package and connected inparallel to the other LED package. Thus, the LED package set and the LEDbulb can emit light having a color temperature that may be changed inaccordance to voltage and current supplied to the LED package set.

Although certain exemplary embodiments and implementations have beendescribed herein, other embodiments and modifications will be apparentfrom this description. Accordingly, the inventive concepts are notlimited to such embodiments, but rather to the broader scope of theappended claims and various obvious modifications and equivalentarrangements as would be apparent to a person of ordinary skill in theart.

The invention claimed is:
 1. An LED package set comprising: a substrate; a first LED package disposed on the substrate and comprising at least one first LED chip; a second LED package disposed on the substrate and comprising at least one second LED chip; and a resistor disposed on the substrate, connected to the first LED package in series, and connected to the second LED package in parallel, wherein the second LED package is connected in parallel to the first LED package and the resistor, and wherein the first LED package is configured to emit light having a higher color temperature than light emitted from the second LED package.
 2. The LED package set according to claim 1, wherein: the substrate comprises a pair of electrode pads; each of the first LED package, second LED package, and the resistor includes a first end and a second end opposing the first end; the first end of the first LED package and the first end of the second LED package are connected to one of the pair of electrode pads; the first end of the resistor is connected to the second end of the first LED package; and the second end of the second LED package and the second end of the resistor are connected to the other one of the pair of electrode pads.
 3. The LED package set according to claim 1, wherein a difference in color temperature between light from the first LED package and light from the second LED package is at least 500 K.
 4. The LED package set according to claim 3, wherein a difference in color temperature between light from the first LED package and light from the second LED package is less than or equal to 1,000 K.
 5. The LED package set according to claim 1, wherein current is distributed to the first LED package and the second LED package depending on a resistance formed by the first LED package and the resistor connected in series, and a resistance of the second LED package.
 6. The LED package set according to claim 5, wherein a color temperature of a mixture of light from the first LED package and the second LED package changes depending on current flowing through the first LED package and current flowing through the second LED package.
 7. The LED package set according to claim 1, wherein: the first LED package comprises a first wavelength conversion portion covering the at least one first LED chip; and the second LED package comprises a second wavelength conversion portion covering the at least one second LED chip.
 8. The LED package set according to claim 7, wherein the first LED chip and the second LED chip are configured to emit light having the same color temperature.
 9. The LED package set according to claim 8, wherein the first wavelength conversion portion and the second wavelength conversion portion comprise phosphors having different color temperatures, respectively.
 10. The LED package set according to claim 1, further comprising a wavelength conversion portion covering each the first LED chip and the second LED chip.
 11. The LED package set according to claim 10, wherein the first LED chip and the second LED chip are configured to emit light having different color temperatures.
 12. The LED package set according to claim 1, wherein the second LED chip has a wider light emitting area than that of the first LED chip. 